Mibes ooeybll



(No Model.) M. OORYELL.

FURNACE-FOR STEAM BOILERS.

No. 326,631. Patented Sept. 22, 1885.

N. PETERS, Phowmmm nur. Wilmington, u z;

.UNITED STATES PATENT OFFICE.

MIYERS OORYELL, on NEW YORK, N.-Y.

FURNACE FO R STEAM-BOILERS.

SPECIFICATION forming part of Letters Patent No. 326,631 dated September22, 1885. Application filed January 26, 1885. (No model.)

.To all whom it may concern:

Be it known that I, MIERS CORYELL, of the city and State of New York,have invented an Improvement in Furnaces for Steam-Boilers, of which thefollowing is a specification.

Practical experience has shown me that furnaces of boilers are greatlyimproved in efficiency by substituting brick Walls for the water-wallsat their sides and front ends, the bricks serving to retain the heat andproduce a more perfect combustion of the fuel, instead of such heatbeing absorbed and conveyed away, and thus lessening the intensity ofthe fire. The cooling effect upon the contents of a furnace surroundedby Water-walls is known to be injurious and fatal to economy, becausethe conductive power of the exposed metal of the water-Wall carries intothe water so much of the heat that the temperature is kept too low forthe complete combustion of coal. In boilers constructed with furnaceshaving brick sides and ends, there is a part of the cylindrical shell ofthe boiler itself, or water or fire tubes, as the case may be, which isdirectly over the fire, or very close to or connected with it. Thisexposed heating-surface is of great conductivity, and absorbs the heatwhich is needed for the volatilization of the bituminous portion of thecoal and its perfeotcombustion. The heat should be retained andaccumulated in order that the required temperature may be obtained for aperfect combustion and union of the carbon and oxygen' in other words,the furnace should be of a non-conducting material, and should retainwithin it the whole of the heat until all the combustible products ofthe coals are thoroughly ignited. Then the highest temperature due toperfect combustion can be directed upon and absorbed by the boilerheating-surface of whatever description.

My improved furnace is applicable to all types of boilers, and Will inoperation add to their efliciency, economy, and safety.

My invention will be readily understood by reference to the accompanyingdrawings.

Figure 1 is a front elevation of the boiler or boiler-front and doors.Fig. 2 is a transverse section at the line 0 C, Fig. 3. Fig. 3isalongitudinal sect-ion at the lines A A B B, Fig. 2, and Fig. 4 is ahorizontal section at the lines :0 my y, Fig. 3.

D D are the furnace or fire chambers, and J J the arches of brick,forming complete covers to the furnaces. These furnaces are constructedunder the boiler-shell. In this form of boiler the arches screen theshell from the furnace heat. In other types they would screen thewater-tubes or other heating-surfaces.

The bridge-wall is shown at E at the end of the grate-bars.

I have shown the side walls, K, of brick, protecting the side portionsof the boiler, so that the heat will not interfere with the downwardcirculation of the water at the sides of the boiler, and there arewing-walls T and an arch, M, to direct the products of combustion asthey pass into the rear ends of the tubes.

The spaces between the tops of the arches J and the under side of theboiler are open for the heated products of combustion to pass up to theboiler, and for the heat that is radiated from the arches to reach suchboiler. Thereby the boiler will be kept in a heated condition, and therewill be no loss of heatingsurface in consequence of the introduction ofthe brick arches, and the boiler will not be liable to injury from toogreat heat.

In order to maintain a gradual circulation of the heated air between theboiler and the tops of the arches, I employ an opening through the frontplate with a pipe and damper, V, leading into the bonnet at the base ofthe smokestack.

I do not claim a furnace havingabrick-arch extending over the fire andthe whole length of the boiler, as this has been made.

I claim as my inventiou- 1. The combination, with the grate-bars,

bridge-wall, and boiler, of two continuous brick arches over the fire,said arches extending from the front wall to the bridge-wall,and forminga shield to prevent the direct action of the fire or products ofcombustion upon the boiler, the space between the arches and the boilerbeing open at the back end for the heated gases to pass in and forwardfrom beyond the bridge-wall and act upon the boiler, substantially asset forth.

2. The combination, with the grate-bars and boiler, .of a bridge-Wall,brick side walls, and a continuous brick arch over the fire-chamber,extending from the front wall without openings to the bridge-wall, therebeing an and damper V, leading to the base of the open space between thearch and the boiler Smokestack, substantiallyas specified. 10 open atthe rear to the flue beyond the bridge- Signed by me this 7th day ofJanuary, A. D. wall, the wing-Walls '1 near the back end of 1885.

5 the boiler, and the arch M and return-fines, MIERS GORYELL.

substantially as set forth. VYitnesses:

3. The combination, with the arches over RoBT. M. HooPER,

the fire-chamber and the boiler, of the pipe OH. F.THIRION.

